Latino youth constitute one of the most vulnerable groups in the nation for the transmission of HIV, experiencing disproportionately high rates of HIV infection. The broad objective of this study is to examine the relationship between differing levels of acculturation and the quality of the parent-adolescent relationship as predictors of HIV risk behavior in Latino youth. The specific aims of the study are (1) to describe the relationship between acculturation and the development of HIV risk behavior in Latino youth, (2) to describe the possible moderating effects of the parent adolescent-relationship as a protective or risk factor for engaging in HIV risk behavior, and (3) to identify if there are subgroup differences among the predictor and outcome variables in a sample of diverse Latino youth. Data will be analyzed from the National Longitudinal Study of Adolescent Health (Add Health); a school-based study with youth from grades 7-12. A Latino sub-sample of 2,387 Latino youth (1,500 Mexican, 450 Cuban and 437 Puerto Rican) will be studied in the context of a prospective design. The Latino youth in grades 7-11 were interviewed twice, one year apart. Statistical analysis will be conducted using a structural equation framework to predict sexual risk behavior, drug use, and alcohol use at Wave II from data collected one year previously at Wave I. Findings from this study aim to provide new insights into the role of the family and acculturation in the prediction and understanding of a range of adolescent risk behaviors related to HIV transmission.